• Journal of Electrical Engineering and Technology
• /
• v.8 no.5
• /
• pp.984-990
• /
• 2013

This paper develops a new Intelligent Electronic Device (IED), and then presents an application method of a monthly load forecasting algorithm on the smart IEDs. A Multiple Linear Regression (MLR) model implemented with Recursive Least Square (RLS) estimation is established in the algorithm. Case Study proves the accuracy and reliability of this algorithm and demonstrates the practical meanings through designed screens. The application method shows the general way to make use of IED's smart characteristics and thereby reveals a broad prospect of smart function realization in application.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.2
• /
• pp.323-329
• /
• 2008

This paper deals with modeling and characteristic analysis of a large-powered electric ship propulsion system. Particularly, system modeling in accordance with the required shipping performance, building-up the equivalent circuit and the power analysis based on load flow have been performed. In addition, abnormal operating condition of short-circuit network is considered for investigating the safety of system components under the over-load condition. Furthermore, protective device like circuit breaker has been specified in order to make the entire system operate normally in case of short-circuit emergency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.561-567
• /
• 2007

This paper deals with the numerical model of a bracing-friction damper system and its deployment using the optimal slip load distribution for the seismic retrofitting of a damaged building. The Slotted Bolted Connection (SBC) type friction damper system was tested to investigate its energy dissipation characteristic. Test results coincided with the numerical ones using the conventional model of a bracing-friction damper system. The placement of this device was numerically explored to apply it to the assumed damaged-building and to evaluate its efficiency. It was found by distributing the slip load that minimizes the given performance indicies based on structural response. Numerical results for the damaged building retrofitted with this slip load distribution showed that the seismic design of the bracing-friction damper system under consideration is effective for the structural response reduction.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.3
• /
• pp.124-130
• /
• 2003

Many structural evaluation procedures of road and airfield pavements use the Falling Weight Deflectometer (FWD) as a critical element of non-destructive deflection testing. FWD is a trailer mounted device that provides accurate data on pavement response to dynamic wheel loads. A dynamic load is generated by dropping a mass from a variable height onto a loading plate. The magnitude of the load and the pavement deflection are measured by a load celt and geophones. And database concerning pavement damage should be enhanced to analyze loss of thickness asphalt layer caused from the plastic deformation of pavement structure, such as cracking or rutting. The prototype FWD is developed, which consists of chassis system, hydraulic loading system, data acquisition and analysis system. This system subsequently merged to from automation management system and is then validated and updated to produce a working FWD which can actually be used in the field.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.51 no.8
• /
• pp.441-448
• /
• 2002

Harmonics studies have been an important aspect of power conversion system analysis and design in recent years. Harmonics using power conversion device, have a harmful effect on power qualify. Nonlinear load such as converter causes harmonic and effects self & other system. There are linear and nonlinear loads in the end-user application. For filter design to reduce harmonics, it is important to understand how loads interact with each other. In this paper, effects on the power conversion system at the low voltage local bus are discussed.

• Proceedings of the KIEE Conference
• /
• 1999.11c
• /
• pp.582-584
• /
• 1999

Generator has synchronized with power Network after build-up output voltage. In order to prevent a current surge when synchronizing, the conditions such as identical no-load voltages identical no-load frequencies and identical phase positions must be met between generator voltage and network voltage. Hydro-Pump generators or Gas-turbine generators, Co-generation Generators that serve peak load of network are synchronized many times. So, Automatic Synchronizing Circuits are very important service. This report apply Diagnosis methods the Automatic Synchronizing Circuits(Device) by developing simulator.

• 한국태양에너지학회:학술대회논문집
• /
• 2008.11a
• /
• pp.273-279
• /
• 2008

The purpose of this study is not only to evaluate thermal performance but also to find the stress behavior of heat transfer tubes under the part load operation in Heat Recovery Steam Generator. Flow analysis was performed to know the behavior of exhaust gas from gas turbine and thermal performance was calculated using distribution of hot exhaust velocity. In addition, tubes temperature during operation were gathered from actual plant to verify the uneven flow distribution under part load operation. Stress analysis was performed using tubes temperature data gathered from actual plant under both part and full load operations to know the stress behavior of tubes.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.660-663
• /
• 2001

There is a mechanical device between the superstructure and substructure of a bridge, which transmit vertical load of superstructure to the substructure and absorb horizontal displacement of super structure due to thermal, dynamic, load, etc. In order to meet two requirements at once, the structure of roller between plates is widely used, and this roller between plates is widely used, and this roller shoe system is known to have smaller horizontal movement resistance than any other type of bridge shoe. In this study, rolling friction resistance characteristics of roller-plate friction system is investigated according to roller dimension, vertical load, hardness and roughness of roller and plate. On the base of the results, the rolling friction resistance of large scale roller shoe is evaluated using model experiment.

• Proceedings of the KIPE Conference
• /
• 1999.07a
• /
• pp.226-229
• /
• 1999

The recent problems such as the rapid increase o electricity consumption, the large variation of electrical loads, and the sitting difficulty for new power plants could become a barrier to stable electrical power supply. Consequently, an electrical load management technology has become important, by which an electricity can be stored during off-peak time and efficiently used during peak time. The technology provides a variety of direct or indirect benefits which include, for utilities, reduction of new power plants, economical electricity production, and improved efficiency and reliability of power system and for consumers, low prices o electricity. The study is to develop a proto-type load management system and its application technology for a peak shaving. In the system, conventional batteries are used as energy storage device.

• Proceedings of the KIPE Conference
• /
• 1999.07a
• /
• pp.210-213
• /
• 1999

A battery is the device that transforms the chemical energy into the direct-current electrical energy directly without a mechanical process. Unit cells are connected in series to obtain the necessary voltage, while being connected in parallel to organize capacity for load current and to decrease the internal resistance for corresponding the sudden shift of the load current. The circular-current, however, could be occurred when the system is driven in parallel. As a result, the new batteries are heated by over-change and discharge, and the over charge current makes to increase the rust of the positive grid and consequently the shortened life of the new batteris would be shown. In this paper, the internal resistance of charge and discharge will be balanced, through inserting the resistance into the system by way of calculation of the changed amount of internal resistance.